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Outward Bound by James Hogan
The Pern series, starting with Dragonquest by Anne McCaffrey. These sound like Fantasy from the title but they are really SF about a colony world long enough after landing that the people have lost their history. Though they will discover it later.
The Warrior's Apprentice by Lois McMaster Bujold
Citizen of the Galaxy by Heinlein
Merchanter's Luck by C.J. Cherryh
None of the above are new - but they are all very, very good.